The patient is a 51-year-old female with comorbidity of schizophrenia. At the age of 41, she underwent surgery for bilateral breast cancer. Both sides were of the Luminal type, with Stage ⅢC on the right and Stage 0 on the left. She started to receive adjuvant chemotherapy but it was interrupted according to her wish. Approximately 3 years ago, she developed carcinomatous pleuritis, multiple liver metastases, and bone metastases. Despite receiving chemotherapy, her condition worsened. A BRACAnalysis revealed pathogenic variants in BRCA2. Upon initiating treatment with olaparib, both her liver metastases and carcinomatous pleuritis have shown reductions, and her tumor markers have also started to decline. Approximately 5 months after treatment with olaparib, it has been possible to continue without any side effects. Olaparib has shown good results in patients with germline BRCA1/2 mutation-positive HER2-negative advanced/recurrent breast cancer who have a history of receiving anthracycline and taxane-based therapies. It was considered that even in recurrent breast cancer, the presence or absence of BRCA1/2 mutations should be actively sought even in advanced cases, and the administration of olaparib should be considered.